Abstract:
The invention concerns a method for preparing mineral colloidal particles in aqueous dispersion with controlled size from a precursor, comprising a) aqueous solution heat treatment of said precursor which is a metal cation mineral salt; b) complexing of the product resulting from a) with at least a water soluble block copolymer comprising a complexing anionic hydrophilic block and at least a stabilising non-ionic hydrophilic block; and c) partial or total hydrolysis of said precursor to obtain a controlled growth of mineral particles in the form of an aqueous dispersion. The invention also concerns the use of said particles as reinforcing fillers for polymers.
Abstract:
A method of enhancing the dispersibility of alpha-alumina monohydrate wherein there is formed a mixture of an alpha-alumina monohydrate, water, and a dispersibility enhancer comprising an effective amount of a monobasic acid, a salt selected from the group consisting of salts having the formula MX wherein M is a polyvalent metal cation constituent for which the solubility product KSP of the corresponding metal hydroxide is less than 10 and wherein X is an anion constituent derived from a monovalent acid having an ionization constant KA greater than 10 and certain phosphorus and antimony chlorides, followed by drying the mixture, without aging, to produce a dried, alpha-alumina monohydrate having advanced water dispersibility.
Abstract:
A process for producing nano sized boehmite aluminas which are stable at alkaline pH values wherein an aqueous medium of a peptized boehmite alumina is treated with a water dispersible polycarboxylic acid polymer and optionally with an organic water dispersible base having a molecular weight ranging from 500 to 3000 and having no more than three basic groupings to produce a treated boehmite alumina which forms a stable sol at a pH of greater than 6, the treated boehmite alumina having a dispersed particle size of less than 500 nm in the sol.
Abstract:
Aqueous dispersion containing transition aluminium oxide as only solid and a dispersant, in which - the transition aluminium oxide is present in the form of aggregates of primary particles, the content of transition aluminium oxide in the dispersion is from 40 to 65% by weight, the aggregates in the dispersion have a mean aggregate diameter of less than 100 nm, - the dispersant contains polyaluminium hydroxychloride, polyaluminium hydroxynitrate and/or polyaluminium hydroxysulphate, the dispersion has a pH of from 3 to 5.
Abstract:
A process for producing nano sized boehmite aluminas which are stable at alkaline pH values wherein an aqueous medium of a peptized boehmite alumina is treated with a water dispersible polycarboxylic acid polymer and optionally with an organic water dispersible base having a molecular weight ranging from 500 to 3000 and having no more than three basic groupings to produce a treated boehmite alumina which forms a stable sol at a pH of greater than 6, the treated boehmite alumina having a dispersed particle size of less than 500 nm in the sol.
Abstract:
The invention provides an aqueous dispersion comprising fumed alumina particles, at least one zirconium compound, and water. The invention further provides a coating composition and a recording medium incorporating the inventive dispersion, as well as a method of preparing the recording medium.
Abstract:
This invention provides metal-rich siliceous compositions and methods of preparing such compositions. The compositions have comprehensibly variable and controllable metal oxide to silica ratios, surface morphology, porosity, and surface area. The method includes preparing a silicic acid, a metal oxide dispersion, and a basic heel solution. The silicic acid and metal oxide dispersion are mixed to create a blend and the blend is controllably added to the basic heel solution to form a siliceous material including colloidal silica-coated metal oxide particles. Factors such as type of silicic acid, concentration and type of metal oxide, and reaction conditions determine properties, including surface morphology and porosity, of the siliceous material.
Abstract:
This invention provides metal-rich siliceous compositions and methods of preparing such compositions. The compositions have comprehensibly variable and controllable metal oxide to silica ratios, surface morphology, porosity, and surface area. The method includes preparing a silicic acid, a metal oxide dispersion, and a basic heel solution. The silicic acid and metal oxide dispersion are mixed to create a blend and the blend is controllably added to the basic heel solution to form a siliceous material including colloidal silica-coated metal oxide particles. Factors such as type of silicic acid, concentration and type of metal oxide, and reaction conditions determine properties, including surface morphology and porosity, of the siliceous material.
Abstract:
Dispersion of sol-derived nano-alumina in an organic solvent mixture containing a 1,2-diol with simple agitation. A thixotropic solution is obtained at 20% alumina in ethylene glycol, while a low viscosity (